（1. National Engineering Research Center for Nanotechnology，Shanghai 200241，China）（2. Shanghai Key Laboratory of Molecular Imaging，Shanghai University of Medicine & Health Sciences， Shanghai 201318，China）
Nano-traditional Chinese medicine is a new research field that is developing rapidly in recent years. The combining of nanotechnology with traditional Chinese medicine produces an enormous influence on the development of medical science. In this paper, the preparation method of orthosiphon stamineus nano-dispersion is developed by shear grinding and high pressure homogenization. A uniform and stable nano-dispersion with average particle size of about 100 nm is obtained. Furthermore, the effect of the nano-dispersion on reducing uric acid (UA) is investigated. Compared with the model group, the inhibition rate of the nano-dispersion on UA is 22.1%, and compared with the water extract experimental group, the nano-dispersion shows a better effect on reducing UA. Additionally, the side effects of the nano-dispersion are evaluated by investigating the liver indexes, which shows that nano-dispersion causes less liver injury through detecting alanine aminotransferase (ALT) and aspartate aminotransferase (AST) of liver compared to that of the model group. Finally, the cytotoxicity of nano-dispersion is proved by cell experiment. The results show that the orthosiphon stamineus nano-dispersion has potential application in reducing UA, which can provide a theoretical basis for the reasearch of nano-dispersion about traditional Chinese medicine.